Yondering

That points to the answer right there - your bullets are probably undersized, which is a common cause of keyholing. Excessive crimp is a possibility too; with soft bullets (plated, swaged, or soft cast bullets) excessive crimp can squeeze the bullet down as it passes. If you still have some of that ammo that caused keyholes - pull a couple bullets and measure their diameter. You may find they are smaller than the bore; they should be the same size or up to a few thousandths larger than the bore.

Shakin - another thing to consider is the newer spring loaded Dillon die. Mine are all older (I haven't bought a Dillon die in ~15 years) and have solidly mounted decapping pins, but a buddy recently bought a 9mm Dillon die set and the sizer die has the decapping rod spring loaded, so it snaps down after pushing out the primer and knocks the primer free. I don't know when they made that change, but it seems pretty slick and I am considering upgrading my dies to that setup.

Can you clarify this? What is the issue? If it's the problem where sometimes the primer seems to stick to the decapping pin and gets pulled back partly into the primer pocket - one thing that helps is to grind a bevel on the end of the decapping pin. The point is to make the tip non-symmetrical so if it tries to pull a primer back into the pocket, it'll be lopsided and will just get knocked off. I've ended up doing this to all the dies I use on my Dillon 550.

Something relevant to keep in mind here too is that a chamber gauge isn't your barrel. You can spend a lot of time and effort to make ammo fit the chamber gauge perfectly, when it may have been just right for your barrel at some point before that. Or in a few cases, your barrel's chamber and throat might be tighter than the chamber gauge. Personally I prefer to do all my checking with the actual barrel it'll be shot in. That's not as convenient, without question, but I know for sure the ammo is exactly what that gun needs. I usually do that to check only my match ammo, and don't check the much larger quantity of my practice ammo except for a few rounds when setting up the dies. I do make sure to check every round that I'll fire in a match though; I've been bitten a couple times when I didn't.

I don't, since I machine my own. If I were looking for someone to do it, I'd probably start with taking the seater plug and a bullet to the local machine shops and asking them to do it. The small "mom and pop" shops will be your best bet. Another option instead of machining the plug is to bed the bullet to it with some sort of strong epoxy like JB Weld. Use release agent on the bullet, and if possible figure out a way to hold the bullet straight with the plug outside of the die; JB Weld inside your seating die won't be any fun even with lots of release agent. That method can work pretty well and gives a perfect match to your bullet.

A comment on the seater die - regardless of brand, in my experience the best results come from having the seater plug cut to match the nose of your bullet. In most cases that means some custom alteration of the plug (or machining a new one), so it'll cost a bit of money and/or time but results are worth it.

Yup, this is your problem - internal case taper varies with different brands of brass. If you force that bullet into the cases with more taper and then use something like a Lee factory crimp die, you'll find that the bullet base gets swaged down (a bad thing) and some of them will even push back out of the case. I load some 170gr and 180gr subsonic 9mm bullets of my own design and ran into the same issues. The solution if you want to use that bullet at that length is to sort brass and only use FC headstamp - FC has more straight wall and the taper is deeper in the case so it handles the long bullets OK. Win, Blazer, and S&B all give problems every time. The other solution is to seat to a long enough OAL that you don't run into the case taper on any brass, but your barrel has to be throated for it and the mags need to accomodate the long OAL.

Different bullet but about the same weight - I use a 103gr coated/cast bullet with 3.2-3.8gr of Clays, depending on the gun, mostly G19 and G34. (Actually in the little G43 I can use 2.6gr because of the light slide.) That is a fairly clean load that shoots accurately in mine.

Glad you got it worked out. I wonder if the issue is the same thing I've run into before, which is different than everyone else mentioned in this thread - sometimes with cast bullets, the bullet's driving band (part that contacts the bore) diameter is large enough that the inside of the seater die scrapes off lead and/or coating, even though you're not trying to apply a crimp. This usually happens with a traditional seat/crimp die that's backed off just barely enough not to crimp if the "alignment" part of the die (just above the crimp taper) is tighter than the cast bullet diameter; the solution is to back the die body out further and lower the seating stem more. On the Dillon seater die though - that shouldn't happen, but maybe you got one that's just a bit tight in the section of the die that aligns the bullet before seating, and unfortunately you can't lower the stem in the body other than having a new one made. That tight section of the die is intended to align bullets with the case during seating, and is usually sized for jacketed bullets, so when tolerances stack up in the wrong direction with a tight die and fat bullets, scraping as you showed can happen. As a side note - fat bullets are a good thing in cast bullets, either lubed or coated, as long as they still chamber easily; undersized bullets can be a problem. Either way, looks like you solved it. Maybe the explanation above will help if you encounter this issue again.

I don't like the look of those either, and with the optic there it seems pointless. On my carry guns at least, (Trij RMR) the optic is the charge handle.

Cool, I'm glad to see that's well understood here. I've noticed on other forums the common take-away for a lot of guys is just "heavier bullets recoil softer" while ignoring the "when power factor is held constant" part. Those guys are usually referring to factory ammo, so the power factor is not constant.

Because "power factor" is a momentum formula, not actually power. To achieve the same momentum, a lighter bullet has to have more energy/power, which affects what the shooter feels. If he's loaded to factory spec (closer to equal power rather than equal momentum), the difference is a lot less pronounced and the light bullet may feel softer.

Yes, need a taller front sight or shorter rear sight.

MM, that makes a lot of sense, and is kind of a fun bit of trivia. Thanks for the info.

Thanks guys. Just wondering about it since it was hard to tell in the pics with not much for a description either. I've had NP3 parts in other guns (like a nice 1911 that was completely finished including internals with NP3) and it definitely slicks them up, but haven't tried it in a Tanfo. Finished the first round of polishing on my stock II frame last night, working on internals now. That hard chrome on the frame polishes nice but takes a lot of work.

That's what I used for milling a Glock for one of these as well. FYI to the OP - 0.140" is a good depth for milling if you don't have that part figured out already. I use the same depth for RMR, DPP, and Vortex optics in Glock slides. Those Vortex optics need locating pins. If you're not set up to mill out the pin bosses (CNC) you'll need to drill and insert pins; this is easiest to do a front and rear pin on the left side. Two pins is adequate for constraining the optic, and avoids any interference with the extractor plunger channel on the right side.

I was just looking at some Tanfo parts online and wondered - is that shiny Xtreme trigger bar plated (chrome, nickel, etc?) or just polished? That does bring up the question of how slick some of these parts could be if one were to send them out for something like NP3 coating, or maybe Micro Slick, etc. Have any of you guys tried that?

Thanks guys!

Cool test, and thanks for sharing the results. As a professional test and development guy myself, I dig this kind of stuff. The Kroil results really surprised me. Like you, I've been using CorrosionX for a number of years with good results. Have you tested any other lubes since posting this? A couple I'd be interested in seeing results for: - Lathe/mill way oil such as Vactra #2 or #4 - STP, Lucas, etc oil additives - synthetic ATF (take your pick) Vactra #2 is hard to come by in small quantities (usually sold in gallons or larger), but I have a gallon of it and am willing to send you some to test (depending on mail regs, not sure) if you're interested. Way oil is specifically designed for sliding surfaces, and is intended to cling to vertical surfaces for long periods of time. The thicker grades might make a gun sluggish, but the light grades might work pretty well on the slide rails, barrel, etc. I've done some similar testing for corrosion resistance rather than wear, but didn't document it as well as you did so I should repeat it. That test was one of the reasons I've been using CorrosionX. Kroil didn't do well at all in that test, and regular Rotella T 15-40 (non-synthetic) actually resulted in rust pits, I think from the detergents in the oil. I didn't test T6, and will include that next time along side Mobil 1.

Thanks john

I wondered the same, especially since they appear to be about the same price. Is the difference just hammer mass, or does one result in more trigger creep than the other, or anything like that?

Can any of you guys tell me - dimensionally what is different between the Bolo and the factory disconnector, other than the pin itself? Is the vertical leg longer, more material in the inner curve, etc?

Primer swipe happens when the barrel unlocks from the slide, long before the ejector comes into play. The swipe is vertical, caused by the barrel and brass dropping downwards in the slide while the firing pin is protruding slightly. It is really common on a lot of different pistols and not something to be concerned about.

Thanks guys, lots of good info there and I really appreciate the input. That helps a lot in understanding what my options are.

Just a comment on Melonite/Tenifer etc pistol slides and visible wear - the nitrocarburizing itself is not black, just bright steel color. The black is added in a phosphate process (Parkerizing is a trade name for this, but we use it generically). The visible wear you see most of the time when one of these slides gets shiny spots is just the parkerizing wearing off; the nitrocarburized surface underneath is intact. I have brought a couple of my Glock slides back to looking new again by just degreasing and parkerizing the surface again, all the visible wear spots disappear. Nitride and nitrocarburizing are often used in industrial applications without a black surface treatment added; those are not visually obvious. Some Porsche crankshafts are treated that way, for example.